Friction draft-gear.



A. STUCKL FRICTION DRAFT GEAR.

APPucmou msu 11111.20. 190s.

2 Pamd 1111.304918.

` and arran passesover the raft ARNOLD STUCKI, 0F PITTSBURGH,PENNSYLVANIA.

FRIGTION DRAFT-GEAR.

Specication of Letters Patent.

Patented Apr. 30, 1918.

Application tiled January 20, 1908. Serial 110,411,648.

.To all rwhom it may concern.'

Be it known thatI, ARNOLD STUGKI, a resident of Pittsburgh, in theYcount of Allegheny and State of Pennsylvama, ave invented a new anduseful Improvement 1n Friction Draft-Gear; and I do hereby' de clare thefollowing to be a. full, clear, and exact description t ereof.

' This invention relates to the friction draft r1 ing or gears forrailway cars.

he object of the invention is to provide a draft gear of the charactervspecified, which has a graduated yet high resistance and anunfailingrelease, and which is simple 'of construction, cheap tomanufacture and durable.

The invention comprises the construction ent of parts hereinafterdescribed an claimed.

In the accompanying drawing Figure l is in lpart a plan view and in parta horizontal longitudinal section through the preferred form of my draftear; Fig. 2 is a longitudinal vertical section of the same; Fig. 3 is atransverse vertical section on the line 3*.3 Fig. 2; Fi 4 is a sectionalperspective view of one of ne friction wed es; Fig. v5 is aperspectiveview of one of t e partitions or relatively stationary friction plates;and Fig. 6 is a sectional view of the rear portion of the draft arshowing a modification.

In Fig. 1 t e draft sills of the car are indicated at 1, and the draftlugs at 2. 3 indicates the usual front follower pla-te, and 4 mdlcatesthe rear follower plate, which latter,

however, is of ecial construction. The coupler stra or yo e is shown at5 and gpar at top and bot-y tgm andaround a suita le saddle 6, bearingagainst the rear follower late 4, as is mon in railway draft mec anism.

The draft gear comprises the follower lates or followers above named,and the ousing or barrel 8, and the friction and ,springmechanismcontained in said housingu The housing preferably is of a.rectangular shape in cross-section, as shown. It is strengthened at top,bottom and sides by ribs or flanges 9. In its preferred form it is openat the rear end as shown in Fi 1 and 2, said rear end having an interlocng or lost motion connection with a, rear fo lower plate 4, so as topermit a limited relative longitudinal movement of these parts for a purose hereinafter described. The drawin s how a special form of connectionformed y a flan e 10 on the rear end of the housing, which flgange attwo or more points is interrupted or cut away as at 30 to permit thepassage of hooks 11 formedon or secured to the follower plates. Theplate and housing are assembled by passing the hooks through theinterrupted spaces in the flange 10, and then giving the arts a partialturn with refei'ence to each ot 1er, thus locking them together. Thehooks 11 are of sufiiclent length to allow a limited relativelongitudinal movement between the housing and the rear follower plate.

he forward end of the housing is flared so as to provide inclined orangular friction Surfaces 12. In the housing and preferably extendingparallel to the faces 12 are angular partition plates or relativelystationary friction plates 14, which are mounted in a manner to permitthem to move laterally with reference to the axis of the draft gear buthaving no movement longitudinally of the housing; or in other words, sothat they move longitudinally with the housing but have freedom ofmovement toward and from the axis of the-housing. This connection may bemade in various ways. As shown in the drawings., the partition orfriction plates.

14 are rovided on their top and bottom edges wlth lugs or bosses 15which project into openings 16 in the top and ttom Walls of the housing.The openings 1 are in the form of slots 1n order that the pl tes 14 withtheir integral lugs can be gotten, n and out. The bosses or lugs 15 arefor ,Y of large size as shown, to give ample s engi-,h and preventcrushing of the metal 1 `ginder the severe stresses to which the draftgear is subjected.

i The stationary friction plates or partitions 14 have inner and outerfriction surfaces preferably but not necessarily parallel to each other,as shown. Between each of these partitions or plates 14 and the frictionsurfaces 12 of the housing are movable friction plates 17, eachcontacting on the outside with the friction surfaces 12 of the housing,and on the inside with the partitions or plates 14. These surfaces arepreferably parallel or at least on a very slight angle,- less than theangle of friction. The plates 17 move in straight 0f which has frictionfaces lines and do not cause lateral movement in any other gert of themechanism, and their resisting e ect is due entirely to the amount offriction enerated on the two rubbing faces thereo Bearin against theinner faces of the stationary riction plates or partitions 1,4 are theangular friction members or Wedges 18. These wedges are s read or causedto exert a ressure against t e partitions 14 by means of) a suitable sreader spring which referably is a dou le elliptical spring 19 avinggraduated leaves so as to give great flexibility. This spring has a.graduated or increasing resistance as it becomes com.- pressed and formswith the friction member a spreader element which acts also as a rictionelement on account of the motion of its rubbin face relative to theelement 14, which is ongitudinally stationary relative to the housing 8.The spring A19 preferably is without bands to economize space, theleaves being held a ainst relative displacement by cooperating osses andsockets fqrmed in said leaves. The spring as an entirety is held againstdisplacement by reason of bein seated between anges 2O on the to anbottom e'dges of the wedges. These anges also serve to strengthen thewedges so the latter may bemade of minimum weight commensurate with thedesired strength and stiffness. The forward or outer ends of the wed esare provided with flanges 21of amp e strength to withstand the batteringof the front follower plate.

To the rear of the friction elements described is a transverse plate orwasher 22, and inter osed between this and the rear follower p ate 4 isa strong helical spring 23 which serves the two-fold purpose of givingthe preliminary resistance to the shortening of the draft gear and as arelease spring for the gear. The drawin s show the Wedges 18 as of'reater length t an the lparallel friction pates 17, so that norma y thefront follower plate contacts with the wedges and moves the same beforeacting on the p arallel friction'plates. This is for the purpose ofsecuring the action of the angular and the parallel friction elements insuccession and givin a Graduated or increasing resistance to theshortening of the gear.

When fully compressed the plate or washer 22 contacts only with theWedges, the shorter friction plates not reaching saidtransverse plate22. While I ha ve dcscribedqind shown a draft gear in which the anularlymovable friction element is first roug t into action, and then thearallel element, or element movable para] el to its opposite parallelfaces, I regard the employment of separate frictional elements inependently movable and each having a rubbing face frictonally contactingwith an independent rubbing surface, as broadly within the spirit of my'invention when arranged with means for moving said elementssuccessively along their mating surfaces to give a graduated andincreasing fricti-onal resistance. f

Fig. 6 shows a modification in which the rear end of the housing isclosed by the wall' 4 which takes the place of the rear follower plate.With this modification, the rear wall acts as an abutment for therelease s ring 23, and also serves the function of a fol ower plate, butthe Vspring 2?l in such case acts merely as a release spring and not togive4 the preliminary resistance as in the pieferred modification.

The drawing shows the gear in its expanded position; that is, when notsubjected to either buing or draft Whensubjected to either of these strthe gear shortens in the usual way an brin its several elements intoaction. The

friction between the wedges and the angl,

quently, the first movement in the shorten ing of the gear is alongitudinal one between the housing and the roar follower plate, thismovement compressing the spring 23. The latter, therefore, acts `as apreliminary re sistance, and as it yields ui'te readily the gear isiiexible to take u s ight shocks. In

the further shortening c the gear, the front follower plate 3 acts ontheouter ends of the wedges 18, forcing the same inwardly between thepartitions or friction plates 14. This movement causes the wedges tocontract or move toward the center, lacing the spreader spring underincreased compression and materially augmenting its initial pressure,tending to force the wedges outwardly. The resistance to the inwardmovement of the wedges is therefore an increasinghone as the gearcontinues to shorten. When t e gear has shortened suliiciently to bringthe ront follower plate into contact with the ends of the. frictionplates 17 the latter are also moved inwardl 'in straight lines andaddthe friction on t eiropposte t arallel faces to the resistancediie tothe increasing shortening of the spring 23 and the increasin resistancedue to the inward movement o the wedges. The amount of friction createdby the movement of the parallel plates 17 is dependent upon th'e outwardthrust or pressure of the partitions 14, due to the spreading action ofthe spring 19 and as the latter is very powerful, especially when thewed es have moved inwardly a considerable distance, a ver 4 largefrictional resistance is added to t e gear by the movement of the lates17.

, The ear descri ed, therefore, brings successive y into action threeseparate resisting contacted only ferent and functions, namely, first,the preliminary resistance of the spring 23 due to the lost motionconnection between the housing and the rear follower plate; second, theresistaznc due to the inward movement of the angular friction members orwedges 18 acting on the relatively stationary friction plates orpartitions 14, this resistance being due to both friction andangularity; and third, the resistance due to the movements of thefriction plates 17. The resistance, therefore, of the gear is agraduated one, being comparatively easy or small at the beginningof theshortening so as to eifectively absorb the slight shocks incident to theoperation 0f trains, and gradually increasing and becoming exceedinglyheavy so as to e ectively take care of heavy shocks. The spring 23 ofcourse gradually increases in its resistance as it shortens.

lVhen the gear is fully compressed or closed the transverse plate orwasher 22 is by the inner ends of the wedges 18 due to the fact thatthese are longer than the parallelifrietion lates 17. Consequently, whenthe gear is re ieved of the bufling or draft stresses, the entirestrength of the spring 23, which is very large on account of itscompressed condition, is exerted against the wedges alone, and as thefriction faces of the latter are on an angle said spring will not 'failto force the wedges outwardly and insure a release of the friction gear.After the wedges are once started, the friction co-efiicient drops toone half, and when the plate 22 strikes 17 it easily overcomes theirresistance, especially since the lateral pressure is already reduced.

The preferred gear utilizes three elements of resistance, cach one beingbased on a difdistinct principle. One is dependent on a coil spring forits resistance. Another, called a parallel friction element, is based onfriction alone, this elementhaving two hearing surfacts` whicharepractically parallel, so thatl the mating friction surfaces on eachside do not close or depart from each other while this element moves.Each plate 17 forms such a parallel friction element. The surfaces couldbe made slightly convergent without affecting the operation materially,as long as; the angle is kept small to exclude the possibility of thelateral pressure causing longitudinal motion, which would destroy thepossibility of succession in the starting. The third or angular frictionelement uses friction and angular-ity in obtaining its resistance, andconsists of a wedge member, creates friction between itself and theinclined mating surface, but also obtains much resistance from itsinward movement. The greater Hc angle, -the greater the resistance. Bymy invention the two independently which in closing not onlymovablefrictio'nal elements, that is, the element with parallel faces, and thespreader element or wedge, are independently movable in a well definedcourse not dependent on play or slack in the gear. This is to bedistinguished from such draft gear constructions as that shown, forinstance in United States Letters Patent No. 391,997, to Westinghouse,in which patent the only frictional movement `whicl1 takes up anysubstantial part of the operative stresses is that of the parallelfriction plates. By the term operative stresses as used in a numberofthe accompanying claims, I mean to include draft or bufiing stressesoperative on the draft gear in the usual manner well understood in theart.

What I claim is:

1. A friction draft gear having a friction element provided withsubstantially parallel opposite friction faces set at an angle to theraft axis, a spreader device including a friction face set atsubstantially the same an le as said faces, and means for moving bot ofsaid friction elements parallel to their friction faces.

2. A friction draft gear having 'a friction element provided with twosubstantially parallel friction faces set at an angle to the draft axis,another element laterally movable relative to the draft axis andprovided with a friction face, another element having friction surfacesmatin friction faces, a spreadier spring opposing the motion of saidother element laterally of the draft axis, and means for moving saidelements parallel to their friction faces.

3. In a friction draft gear the combination of two independently movablefriction elements provided with friction faces, a partition platebetween said elements and provided with opposite frictional surfacesmating-with the faces of each of said elements, and means for firstmoving one of said friction elements to provide a frictional resistance,and then moving the other of said friction elements to` increase saidfrictional resistance. y

4. A friction draft gear having a friction element provided withsubstantially parallel opposite friction faces, a spreader elementhaving a friction face set at an angle to the draft axis, and a followernormally in contact with one of said elements and out of contact withthe other, and arranged on a with each of said shortening of the gear tosuccessivel move and sai faces, means for opposing a yielding resistanceto the motion of said other element laterall of the draft axis, and afollower normal y and arranged to first move said element against saidresistance parallel to its friction face and then move said firstmentioned element parallel to its friction faces.

6. A friction draft gear having a housing, front and rear followerplates, and a lost motion connection between one of said follower latesand said housing, successively movab e friction elements in saidhousing, and a s ring between said follower plate elements and arrangedto act on said elements successively to return the same to normalosition.

7. A friction draft gear comprising a housing having friction surfaces,follower plates friction wedges in the housing, a spreader springtherefor, angularly ar ran ed friction plates coperating with said weges' and arranged to move transversely of the housin but having nomovement 1ongitudinally t ereof, and a friction plate movable on ashortenin of the gear and contacting frictionally with the -frictionface 0111 said housing and said angular friction p ate.

8. A friction draft gear comprising a housing having friction surfaces,angular friction wedges, a spreader spring therefor, angularly arrangedfriction plates contacting with said wedges and arranged to movetransversely of the ear but not longitudinally thereof, movab e frictionplates interposed between said angular friction plates and the frictionsurfaces of the housing, and a follower plate arranged to contact within contact with said other element V said wedges and said movablefriction plates successively.

9. A friction drafty gear comprising a housing, follower plates, angularfriction wedges in the housing, a spreader spring therefor, angular-lyarran contacting with said we ges and arranged to have movementtransversely but not longitudinally of the gear, movable friction platesinterposed between the housing and said angularly arranged frictionplates, and a spring interposed etween the inner ends of said wedges andmovable friction plates and the rear follower plate.

10. A friction draft gear comprising a housing, angular friction wedges,a spreader spring therefor, angularly arranged friction p atescontacting with said wedges and arran ed to move transversely but notlongitudinally of the housing, friction plates having parallel facesinterposed between said angu ar friction plates and the housing andcontactin therewith, said arallel friction plates an wedges being ofierent lengths so as to be operated in succession, a front followerplate arranged to contact with said wedges and parallel friction plates,a transverse plate at the inner ends of said wedges and parallelfriction plates, a rear follower plate, and a spring interposed betweensaid follower plate an the `transverse plate at the rear ends of thewedges and parallel friction plates.

In testimony'whereof, I the said Armour STUQKI have hereunto set myhand.

ARNOLD STUCKI.

Witnesses:

ROBERT C. Torrini, J. R. Kaum.

ed friction plates i

